Use of on-chip frame buffer to improve LCD response time by overdriving

Abstract

A method and system is disclosed for improving the response time of displays, such as liquid crystal displays (LCDs). The method includes receiving a target picture frame and comparing it to a current picture frame. If the comparison shows that a display may be unable to transition from a current pixel intensity level to a target pixel intensity level within a specified time period, then the pixels that correspond to those current pixel intensities that may not be reach target pixel intensities may be overdriven. This overdriving of one or more pixels may allow the pixel to reach the target pixel intensity within the specified time period.

1. A method for overdriving a display, comprising:
 receiving a target picture frame that corresponds to target pixel intensity levels to be displayed on a display for each of the plurality of pixels of the display; 
 comparing the target picture frame with a current picture frame that corresponds to current pixel intensity levels currently displayed on the display for each of a plurality of pixels of the display; 
 determining adjustments to be made to the target picture frame based on a comparison of the target picture frame and the current picture frame; and 
 generating an adjusted picture frame comprising the adjustments determined to be made to the target picture frame by overdriving the plurality of pixels to overdrive pixel intensity levels that exceed the target pixel intensity levels of the plurality of pixels if it is determined that the target pixel intensity levels cannot be reached in a given period of time. 
 
     
     
       2. The method of  claim 1 , wherein comparing the target picture frame with the current picture frame comprises performing a pixel-by-pixel comparison of the target picture frame and the current picture frame. 
     
     
       3. The method of  claim 2 , wherein determining adjustments to be made to the target picture frame comprises:
 accessing a lookup table adapted to store pixel intensity levels corresponding to first pixel intensity levels for generating a first image on a display, second pixel intensity levels for generating a second image on the display, and overdrive pixel intensity levels for transitioning between the first and second pixel intensity levels; 
 comparing the pixel-by-pixel comparison of the target picture frame and the current picture frame with the first and second pixel intensity levels accessed in the lookup table; and 
 retrieving the overdrive levels associated with any matches between the pixel-by-pixel comparison of the target picture frame and the current picture frame with the first and second pixel intensity levels. 
 
     
     
       4. The method of  claim 3 , wherein the adjustments determined to be made to the target picture comprise overdriving any pixel of the display that corresponds to a match between the pixel-by-pixel comparison of the target picture frame and the current picture frame with the first and second pixel intensity levels. 
     
     
       5. The method of  claim 3 , wherein the lookup table is adapted to store overdrive levels specific to the display. 
     
     
       6. The method of  claim 3 , wherein the lookup table is adapted to store overdrive levels for a plurality of displays. 
     
     
       7. The method of  claim 3 , wherein the lookup table is adapted to store overdrive levels for a generic display. 
     
     
       8. The method of  claim 1 , wherein the adjustments determined to be made to the target picture comprise overdriving select target pixel intensity levels to a specified higher level. 
     
     
       9. The method of  claim 8 , wherein the specified higher level corresponds an overdrive level related to any difference between the current pixel intensity level and the target pixel intensity level for any one of the plurality of pixels of the display. 
     
     
       10. The method of  claim 1 , comprising generating an achievable picture frame that corresponds to actual pixel intensity levels to be displayed on a display for each of the plurality of pixels of the display. 
     
     
       11. The method of  claim 10 , comprising replacing the current picture with the achievable picture frame. 
     
     
       12. The method of  claim 1 , comprising transmitting the adjusted picture frame to the display for generation of an image. 
     
     
       13. A method for displaying an image, comprising:
 receiving a target picture frame comprising target pixel intensity levels corresponding to an image to be displayed; 
 comparing the target picture frame with a current picture frame comprising current pixel intensity levels corresponding to a displayed image; 
 determining if each of a plurality of pixels in a display is able to transition from the current pixel intensity levels to the target picture intensity levels in a specified time; and 
 generating an adjusted pixel intensity level corresponding to each of the plurality of pixels of the display determined to be unable to transition from the current pixel intensity levels to the target picture intensity levels in the specified time, wherein the adjusted pixel intensity level comprises an overdrive level at an intensity level higher than the target pixel intensity level for each of the plurality of pixels in the display determined to be unable to transition from the current pixel intensity levels to the target picture intensity levels in the specified time. 
 
     
     
       14. The method of  claim 13 , wherein the overdrive level is based on pixel transitioning characteristics of the display. 
     
     
       15. The method of  claim 13 , comprising transmitting an adjusted picture frame to the display to generate an image, wherein the adjusted picture frame comprises the target picture frame overwritten by any adjusted pixel intensity levels. 
     
     
       16. The method of  claim 13 , wherein the specified time comprises the time required for the display to refresh each of the plurality of pixels of the display. 
     
     
       17. A signal adjusting circuit, comprising:
 a lookup table adapted to store pixel intensity levels corresponding to first pixel intensity levels for generating a first image on a display, second pixel intensity levels for generating a second image on the display, and overdrive pixel intensity levels for transitioning between the first and second pixel intensity levels; 
 a buffer adapted to store a current picture frame that corresponds to current pixel intensity levels for each of a plurality of pixels of the display at a first time; and 
 adjustment circuitry adapted to:
 receive a target picture frame that corresponds to target pixel intensity levels for each of the plurality of pixels of the display at a second time; and 
 modify the target picture frame to generate an adjusted picture frame containing adjustments to the target pixel intensity levels by overdriving pixels of the display to overdrive pixel intensity levels that exceed the target pixel intensity levels of the pixels if it is determined that the target pixel intensity levels of the pixels cannot be reached in a given period of time. 
 
 
     
     
       18. The signal adjusting circuit of  claim 17 , wherein the adjustment circuitry is adapted to actively retrieve the target picture frame. 
     
     
       19. The signal adjusting circuit of  claim 17 , wherein the adjustment circuitry is adapted to generate an achievable picture frame corresponding to actual pixel intensities generated on the display in conjunction with the adjusted picture frame. 
     
     
       20. The signal adjusting circuit of  claim 19 , wherein the adjustment circuitry is adapted to transmit the adjusted picture frame to a display for generation of an image. 
     
     
       21. The signal adjusting circuit of  claim 19 , wherein the adjustment circuitry is adapted to update the buffer with the achievable picture frame. 
     
     
       22. An electronic device, comprising:
 a display comprising a plurality of pixels; 
 a buffer adapted to store a current picture frame that corresponds to current pixel intensity levels for each of the plurality of pixels of the display at a first time; and 
 adjustment circuitry adapted to:
 receive a target picture frame that corresponds to target pixel intensity levels for each of the plurality of pixels of the display at a second time; 
 calculate an adjusted picture frame containing adjustments to the target pixel intensity levels by determining pixel intensity levels corresponding to first pixel intensity levels for generating a first image on a display, determining second pixel intensity levels for generating a second image on the display, and determining overdrive pixel intensity levels for transitioning between the first and second pixel intensity levels; and 
 modify the target picture frame to generate the adjusted picture frame containing adjustments to the target pixel intensity levels to overdrive pixels of the display to overdrive pixel intensity levels that exceed the target pixel intensity levels of the pixels if it is determined that the target pixel intensity levels of the pixels cannot be reached in a given period of time. 
 
 
     
     
       23. The signal adjusting circuit of  claim 22 , wherein the adjustment circuitry is adapted to generate an achievable picture frame corresponding to actual pixel intensities generated on the display in conjunction with the adjusted picture frame. 
     
     
       24. The signal adjusting circuit of  claim 22 , wherein the adjustment circuitry is adapted to transmit the adjusted picture frame to the display for generation of an image.